FR3014884A1 - - Google Patents

Abstract

The present invention relates to composite particles comprising: a pigment; at least one ionic synergist adsorbed on the surface of the pigment; and at least one ionic polymer coating the surface of the pigment comprising the at least one synergist, wherein the at least one synergist and the at least one polymer have opposite charges, and wherein, in the composite, the total charge at least one polymer is greater than the total charge of the at least one synergist. The invention also relates to dispersions and inkjet ink compositions comprising the composite particles.

Description

Field of the Invention Self-dispersible pigment composites, and dispersions and inkjet ink compositions comprising such composites are disclosed herein.

BACKGROUND Pigments are generally not readily dispersible in water and most solvents. There has been much effort in the development of dispersant systems to obtain stable pigment dispersions to render the pigments useful for applications such as inkjet printing, including the addition of dispersants external or a modification of the pigment to make them self-dispersible. However, with the increasing use and diversity of applications requiring such pigments, eg high speed printing, printing on various substrates, there is still a need to develop novel compositions for stable pigment dispersions. SUMMARY An embodiment provides composite particles comprising: a pigment; at least one ionic synergist adsorbed on the surface of the pigment; and at least one ionic polymer coating the surface of the pigment comprising the at least one synergist, wherein the at least one synergist and the at least one polymer have opposite charges, and wherein, in the composite, the total charge At least one polymer is greater than the total charge of the at least one synergist. According to an alternative embodiment, the coating comprises the at least one polymer partially coating the pigment. According to another alternative embodiment, the coating comprises the at least one polymer encapsulating the pigment. The at least one synergist is anionic and the at least one polymer is cationic. According to an alternative embodiment, the at least one synergist is cationic and the at least one polymer is anionic.

The at least one ionic synergist is chosen from the salts of carboxylic acids, sulfonic acids, phosphonic acids, hydroxyls, and amines. The particles have an average particle size in the range of 50 nm to 600 nm.

Alternatively, the particles have a mean particle size in the range of 50 nm to 400 nm. According to another variant, the particles have a mean particle size in the range from 50 nm to 200 nm.

In these particles, the pigment is an organic pigment. In these particles, the at least one ionic polymer is selected from the salts of carboxylic acids, sulfonic acids, phosphonic acids, hydroxyls, and amines. In these particles, the at least one polymer is anionic and is selected from acrylate-based polymers, polyurethanes, and polyesters. In these particles, the at least one polymer has an acid number of at least 20, and the at least one polymer is selected from polyurethanes. According to another variant embodiment, in these particles, the at least one polymer has an acid number of at least 50, and the at least one polymer is chosen from acrylate-based polymers. In these particles, the synergist / pigment weight ratio is in the range of 0.01 to 0.5. In these particles, the polymer / pigment weight ratio is in the range of 0.01 to 3. In these particles, the pigment and the at least one synergist have at least one ionic group attached. In these particles, the at least one synergist is a derivative of the pigment. In these particles, the pigment and the at least one synergist are derivatives of the same chromophore. The invention also relates to a dispersion comprising the composite particles described above. In this dispersion, after aging at 60 ° C. for 7 days, the average particle size of the composite particles increases by at most 200% of the initial average particle size. Alternatively, in this dispersion, following aging at 60 ° C for 7 days, the average particle size of the composite particles increases by at most 100% of the initial average particle size. According to another variant, in this dispersion, following aging at 60 ° C. for 7 days, the average particle size of the composite particles increases by at most 50% of the initial average particle size. According to another embodiment, in this dispersion, following aging at 60 ° C. for 7 days, the viscosity of the dispersion increases by at most 100% of the initial viscosity. According to still another variant, in this dispersion, following aging at 60 ° C. for 7 days, the viscosity of the dispersion increases by at most 50% of the initial viscosity. In this dispersion, the pigment is present in the dispersion in an amount ranging from 1% to 30%. The invention also relates to an ink jet ink composition comprising the composite particles, as described above, in a liquid vehicle. In this inkjet ink composition, the liquid vehicle is an aqueous vehicle. This inkjet ink composition comprising the dispersion as defined above.

Another embodiment provides a dispersion comprising: a copper phthalocyanine pigment; and a modified copper phthalocyanine additive present in an amount of at least 3% by weight based on the total weight of the pigment, the additive being capable of dispersing the pigment in an aqueous solution, wherein the copper phthalocyanine additive modified compound comprises at least one substituent selected from 10 - [SO 3] X +, - [CO 2] X +, - [CH 2 NR 1 R 2 R 3] + Y -, - [CH 2 NH (CH 2) n NR 1 R 2 R 3 + Y, and - [SO 2 NH (CH 2) 2 NR 1 R 2 R 3] + Y-, and wherein X + is selected from hydrogen, an alkali metal, ammonium, and an alkylammonium; n = 1-6; R1, R2 and R3 are independently selected from hydrogen and C5-C6 alkyl and cycloalkyl radicals; and Y is independently selected from chloride, bromide, sulfate, hydrosulfate, acetate, propionate, and a C 1-6 alkylsulfonate. In this dispersion, the modified copper phthalocyanine additive is present in a amount in the range of 3% to 8% by weight based on the total weight of the pigment. Alternatively, in this dispersion, the modified copper phthalocyanine additive is present in an amount ranging from 3% to 5% by weight based on the total weight of the pigment. In this dispersion, R 1, R 2 and R 3 are independently selected from hydrogen, C 1 to C 12 alkyl, and C 5 to C 6 cycloalkyls. In this dispersion, the modified copper phthalocyanine additive has 1-4 substituents. The invention also relates to an ink jet ink composition obtained from the dispersion as just defined above. Another embodiment provides a method for making composite particles comprising: combining a pigment with at least one ionic synergist adsorbed on the surface of the pigment; the coating of the surface of the pigment comprising the at least one synergist with at least one ionic polymer, wherein the at least one synergist and the at least one polymer have opposite charges, and wherein in the composite, the total charge of the at least one polymer is greater than the total charge of the at least one synergist.

The invention finally provides a process for preparing a dispersion, comprising: combining a copper phthalocyanine pigment and a modified copper phthalocyanine additive present in an amount of at least 3% by weight based on the total weight pigment, wherein the modified copper phthalocyanine additive comprises at least one substituent selected from -fso3nC, - [CO2] -X +, - [CH2NR1R2R3] + Y [CH2NH (CH2) nNR1R2R3 + Y and - [SO2NH (CH2) nNR1R2R3] wherein X + is selected from hydrogen, an alkali metal, ammonium, and an alkylammonium; n = 1-6; R1, R2 and R3 are independently selected from hydrogen and C5-C6 alkyl and cycloalkyl radicals; and Y- is independently selected from C1 to C6 chloride, bromide, sulfate, hydrosulfate, acetate, propionate, and alkylsulfonate, and the dispersion of the copper phthalocyanine pigment in an aqueous solution. According to this method, the modified copper phthalocyanine additive is present in an amount ranging from 3% to 8% by weight based on the total weight of the pigment. According to this method, the viscosity or particle size of the dispersion after heat aging for 6 weeks at 60 ° C does not change by more than 20% with respect to the dispersion viscosity at the time of dispersion. According to a variant of this process, the viscosity or the particle size of the dispersion following heat aging for 6 weeks at 60 ° C. does not change by more than 10% with respect to the viscosity of the dispersion at the moment. of dispersion. DETAILED DESCRIPTION Pigment composites are disclosed here in which a pigment has adsorbed on its surface at least one synergist and is further coated with a polymer. Accordingly, one embodiment provides composite particles comprising: a pigment; at least one ionic synergist adsorbed on the surface of the pigment; and at least one ionic polymer coating the surface of the pigment comprising the at least one synergist, wherein the at least one synergist and the at least one polymer have opposite charges, and wherein, in the composite, the charge The total of the at least one polymer is greater than the total charge of the at least one synergist. In one embodiment, the pigment is an organic pigment, for example an organic colored pigment. Typically, an organic colored pigment comprises an organic chromophore group which may be further substituted with one or more substituents. In general, the organic chromophore group provides the essential color of the pigment. In one embodiment, the one or more substituents (for example, a functional group) linked to the chromophore further define the specific color and shade of the pigment and differentiate it from other pigments in the same class of pigments. In one embodiment, the organic chromophore group is that portion of the dye structure to which the substituents are bonded and may be considered to be the framework or backbone structure of the pigment. In one embodiment, the synergist is structurally similar to the pigment. In one embodiment, a "structurally similar" synergist contains an identical structural section and a separate structural section. In one embodiment, the identical structural section comprises at least 50% of the total molecular weight of the pigment, for example at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% of the total molecular weight of the pigment. In one embodiment, by providing a synergist having at least one or more components that are structurally similar to the pigment, improved dispersion stability is achieved. In one embodiment, the synergist is a derivative of the pigment. In one embodiment, the synergist is structurally similar to the pigment chromophore, for example a chromophore derivative. For example, the synergist may be a dye. In one embodiment, both the pigment and the synergist are derivatives of the chromophore.

In one embodiment, the synergist is a dispersant, for example a material separated from the pigment that is capable of achieving stable pigment dispersions in a liquid medium. The synergist is therefore not a material produced during pigment preparation using, for example, known mixed coupling techniques. In one embodiment, the synergist is soluble in a liquid medium, for example an aqueous solution. The ink jet ink composition may also include multiple pigments and several synergists. However, the structural relationships discussed above should also apply to these mixtures. For example, if the inkjet ink composition comprises two pigments, the ink jet ink composition also comprises at least two synergists, at least one synergist having a component that is identical (or structurally similar) to that of the first pigment and at least one synergist having a component that is identical (or structurally similar) to that of the second pigment. If a combination of two pigments having the same component is used, then only one synergist is needed, which should also have the same component. Also, more than one synergist can be used for a single pigment, as long as the components of each synergist are the same as the pigment component. Other combinations and mixtures of pigments and synergists, satisfying the structural relationships indicated above, are also possible. In one embodiment, the synergist is adsorbed on the surface of the pigment as long as it remains adsorbed even after aging, for example, for at least 7 days. In one embodiment, the dispersion maintains the adsorbed synergist on the pigment surface following aging of the dispersion for at least 7 days at 60 ° C. While not wishing to be bound by any theory, the structural similarity between the pigment and the synergist results in the synergist having a strong affinity for the pigment. In one embodiment, the high affinity assists adsorption of the synergist on the surface of the pigment. In one embodiment, this high affinity may take the form of Van der Waals interactions (e.g., dipole-dipole interactions). In one embodiment, the synergist further comprises at least one ionic group, allowing further interactions between the pigment and the synergist, including one or more ionic interactions / bonds, hydrogen bonds, and acid / base interactions / reactions. . In one embodiment, both the pigment and the synergist have at least one ionic group, thereby performing interactions as described herein (e.g., Van der Waals interactions, ionic interactions / bonds, acid / base interactions / bonds, and hydrogen bonds). Both the synergist and the polymer are ionic since they contain ionic groups. "Ionic" may be either anionic or cationic and may be associated with a counter-charge counter-ion, including inorganic or organic counter-ions, such as Na +, K +, NH4 +, NR'4 +, acetate, NO3-, Wherein R 'represents hydrogen or an organic group, such as a substituted or unsubstituted aryl or alkyl group. In one embodiment, an "ionic group" may also refer to an ionizable group, which is a group capable of forming an ionic group (eg a salt) in the use medium, for example a liquid vehicle. The ionic group may include ionic groups (eg anionic or cationic) mixed with the respective ionizable groups. Anionic groups are negatively charged ionic groups that can be generated from groups having ionizable substituents that can form anions (anionizable groups), such as acidic substituents. Cationic groups are positively charged organic ion groups that can be generated from ionizable substituents that can form cations (cationizable groups), such as protonated amines. In one embodiment, at least during and after the coating of the pigment surface with the polymer, the ionic groups of both the synergist and the polymer are present as salt. In one embodiment, the ionic synergist and ionic polymer ionic groups have opposite charges, which allows the polymer and the ionic synergist to interact in one or more ways, including ionic interactions / bonds, Van der Waals interactions, acid / base interactions / bonds, and hydrogen bonds. In one embodiment, the ionic synergist and the ionic polymer comprise at least one ionic group selected from the salts of carboxylic acids, sulfonic acids, phosphonic acids, hydroxyl, and amines, moment that the selection results in the synergist and the polymer having opposite charges in the composite. Specific examples of the anionic groups include -000-, -SO3-, -SO03-, -HPO3, -0PO32- or -PO32, and specific examples of the anionizable groups include -COOH, -SO3H, -PO3H2, -R '. SH and -R'OH, where R 'is hydrogen or an organic group such as a substituted or unsubstituted aryl or alkyl group. Also, specific examples of cationic or cationizable groups include alkyl- and arylamines (primary, secondary and / or tertiary) which can be protonated in an acidic medium to form ammonium groups -NR134- where R 'is selected from And organic groups such as a substituted or unsubstituted aryl group (for example, C 5 to C 6 aryl groups such as phenyl, naphthyl) or alkyl (for example, C 1 to C 12 alkyl groups). Other cationic groups include pyridinium groups, quaternary ammonium groups, sulfonium groups (-SR'21, phosphonium groups (-PR '3+), and corresponding cationizable groups. also use quaternized cyclic amines, quaternized aromatic amines, N-substituted pyridinium compounds such as N-methylpyridyl, Examples of cationic counterions are disclosed in US Patent No. 6,221,143. Other organic groups include those described in US Patent No. 5,698,016. Examples of pigment / synergist combinations include those described in US Pat. Nos. 7,223,302, 8,048,213 and 8,133,311. In one embodiment both the pigment and the synergist are azo compounds (e.g., monoazo, diazo). In one embodiment, the azo compounds further comprise at least one group selected from the group consisting of toacetamides, hydroxypyridones, pyrazolones, hydroxynaphthalenes. In one embodiment, these azo compounds further comprise at least one aromatic group optionally substituted with at least one ionic group (salt) or ionizable group and mixtures thereof, as disclosed herein. In one embodiment, both the pigment and the synergist comprise a group selected from quinolonoquinolonyls, quinacridonyls, quinacridonylenes, and phthalocyanines. In yet another embodiment, the pigment comprises a compound of the formula: wherein P1-P6 are substituent groups of the azo pigment, and wherein P1 and P5 are not alkoxy groups; and the synergist is of the formula: wherein S1-S6 are substituent groups of the synergist, at least one of S2-S4 comprises an ionic or ionizable group, S5 = P5, and S6 = P6 . In one embodiment, for both the dyestuff and the synergist, R is a C1 to C6 alkyl, for example methyl. Another embodiment provides a dispersion comprising a copper phthalocyanine pigment and a modified copper phthalocyanine additive, which is a synergist. In one embodiment, the modified copper phthalocyanine additive is present in an amount of at least 3% by weight based on the total weight of the pigment, the additive being capable of dispersing the pigment. In one embodiment, the modified copper phthalocyanine additive is present in an amount ranging from 3% to 8% by weight based on the total weight of the pigment, for example in an amount in the range from 3% to 7%, 3% to &%, or 3% to 5% by weight based on the total weight of the pigment. In one embodiment, the modified copper phthalocyanine additive is modified by substitution of a phthalocyanine ring. The additive comprises at least one substituent which may be anionic or cationic. In one embodiment, the at least one substituent is cationic and includes ammonium ions of formulas such as - [CH2NR1R2R3] + Y-, - [CH2NH (CH2) nNR1R2R3] and - [SO2NH (CH2) nNR1R2R3] + Y, wherein R ', R2 and R3 are independently selected from hydrogen, C5 to C6 alkyls and cycloalkyls. In one embodiment, the alkyls are selected from C 1 to C 2 alkyls, for example C 1 to C 6 alkyls. In one embodiment, R 1, R 2 and R 3 are independently selected from C 1 to C 2 alkyls, for example C 1 to C 6 alkyls. In one embodiment, the anionic counter-ion, Y-, is independently selected from chloride, bromide, sulfate, sulfhydrate, acetate, propionate, and C1-C6 alkylsulfonate. In one embodiment, the at least one substituent is anionic and is selected from - [SO2] X +, - [CO2] -> C, wherein the counterion, X +, is selected from hydrogen, a metal alkali (eg Na +, K +), ammonium, and alkylammonium. In one embodiment, "alkylammonium" may be selected from mono-, di-, tri- and tetraalkylammoniums, wherein each alkyl may be selected from C1 to C6 alkyls. Another embodiment provides a dispersion comprising, consisting essentially of, or consisting of, water; A copper phthalocyanine pigment; and a modified copper phthalocyanine additive present in an amount of at least 3% by weight based on the total weight of the pigment, the additive being capable of dispersing the pigment, wherein the modified copper phthalocyanine additive comprises at least one substituent selected from - [SO3] X +, - [002] X +, - [CH2NR1R2R3] + Y-, - [CH2NH (CH2) nNR1R2R3] + y-, and - [SO2NH (CH2) 'NR1R2R3] + Y, and which X + is selected from hydrogen, an alkali metal, ammonium, and an alkylammonium; n = 1-6; R1, R2 and R3 are independently selected from hydrogen and C5-C6 alkyl and cycloalkyl radicals; and Y- is independently selected from chloride, bromide, sulfate, hydrosulphate, acetate, propionate, and C1 to C6 alkylsulfonate. In one embodiment, the modified copper phthalocyanine additive comprises: -4 substituents, for example 13 substituents, or 1-2 substituents. In another embodiment, the modified copper phthalocyanine additive comprises a single substituent. In one embodiment, the modified copper phthalocyanine additive is selected from DB86, DB87, DB199 Direct dyes, Acid Blue dyes such as AB185 and AB249, and cationic phthalocyanine dyes such as the Basic Blue 140. For example, Direct Blue 199, which is a tetrasulfonated copper phthalocyanine dye, can be adsorbed on the surface of the copper phthalocyanine pigment. In one embodiment, the ionic polymer comprises at least one monomer having an ionic or ionizable group and mixtures thereof. The resulting polymer may be either polyanionic or polycationic and is present in such an amount that in the composite the total polymer load is greater than the total charge of the at least one ionic synergist. In one embodiment, the at least one polymer coating the pigment surface also interacts with the at least one synergist. In one embodiment, the interaction takes the form of an ionic interaction (e.g., an ionic bond). This ionic bond can occur when the polymer has a charge opposite to that of the synergist. In one embodiment, the interaction between the polymer and the pigment comprises an ionic bond and is further amplified by one or more Van der Waals interactions, hydrogen bonds, and acid / base interactions / reactions. In one embodiment, by providing a composite having the polymer with a total charge greater than the total charge of the at least one synergist, the polymer can be allowed to have a sufficient charge to interact with the adsorbed synergist on the surface. and sufficient excess filler to render the self-dispersible composite pigment in a liquid vehicle, for example an aqueous vehicle. In one embodiment, the polymer comprises one or more monomers having acidic groups (eg carboxylic acid) and their salts. In one embodiment, the polymer has an acid number of at least 20 or at least 50. In one embodiment, the polymer is selected from acrylate polymers having an acid number. in at least 50. In another embodiment, the polymer is selected from polyurethanes having an acid number of at least 20. In one embodiment, the polymer is selected from polyelectrolytes and dispersants.

In one embodiment, the polymer coating encapsulates the pigment. In another embodiment, the coating partially covers the pigment, for example in one or more discontinuous phases. Analytical techniques for measuring the charge of the particles can be used to determine whether a sufficient amount of polymer has been added to form a desired coating. Examples of such measurements are disclosed in US Patent No. 6,641,656. For example, the zeta potential of the pigment and / or the pigment / synergist combination can be measured. Since the ionic polymer is added to the pigment or pigment / synergist with a known or predetermined zeta potential, a change in surface charge can be expected because the added polymer has a charge opposite to that of the synergist. Other methods can also be used to determine how much of the polymer to add.

In one embodiment, the amount of synergist is in the range of 0.5% to 50% by weight based on the total weight of the pigment, for example 0.5% to 30%, 0.5% at 20%, 0.5% to 15%, 0.5% to 10%, 1% to 50%, 1% to 30%, 1% to 20%, 1% to 15%, 10% to 10%, 2% to 50%, 2% to 30%, 2% to 20%, 2% to 15%, or 2.0% to 10% by weight based on total weight of the pigment. In one embodiment, the amount of synergist is in the range of 1% to 30% or 2% to 15% by weight based on the total weight of the pigment. In one embodiment, the polymer is present in an amount ranging from 1% to 500% by weight based on the total weight of the pigment, for example from 1% to 300%, from 1% to 200%, from 1% to 100%, from 5% to 20,500%, from 5% to 300%, from 5% to 200%, from 5% to 100%, from% to 500%, from 10% to 300%, from 10% to 200%, 10% to 100%, 15% to 500%, 15% to 300%, 15% to 200%, 15% to 100% by weight based on the weight of the pigment. In one embodiment, the polymer is present in an amount ranging from 5% to 300%, from 10% to 200%, or from 15% to 100% by weight based on the total weight of the pigment. One embodiment provides a dispersion comprising the composite particles described herein. The amount of each component of the composite may vary depending on the desired properties (e.g., inks containing the dispersions and / or the resulting printed image). In one embodiment, the amount of pigment is in the range of 0.1% to 30% based on the total weight of the dispersion (or other amounts indicated herein). In one embodiment, in a dispersion, the synergist / pigment weight ratio is in the range of 0.01 to 0.5. In another embodiment, in a dispersion, the polymer / pigment weight ratio is in the range of 0.01 to 3.

In one embodiment, the composite particles have an average particle size suitable for an ink jet printing ink, for example sufficient for good jet properties while allowing suitable optical densities. In one embodiment, the composite particles have an average particle size in the range of 50 nm to 600 nm, for example 50 nm to 500 nm, 50 nm to 400 nm, 50 nm to 300 nm, or 50 nm to 200 nm. In one embodiment, the composite pigment disclosed herein provides sufficiently stable pigment dispersions. In one embodiment, following aging at 60 ° C. for 7 days, the average particle size of the composite particles increases by at most 200% or at most 100% of the initial average particle size, for example by at most 75% of the initial average grain size, or at most 50% of the initial average grain size. In another embodiment, following aging at 60 ° C. for 7 days, the viscosity of the dispersion increases by not more than 100% of the initial viscosity, for example not more than 75% of the initial viscosity, or not more than 50% of the initial viscosity. The average particle size or "initial" viscosity refers to the particle size or viscosity measured within 24 hours of the preparation of the composite particle stored at room temperature. In one embodiment, the at least one ionic polymer coating the pigment surface is obtained by combining the pigment with the polymer itself, as opposed to combining the pigment with monomers which are then polymerized. As a result, the polymerization can be carried out without interference of the pigment. This may also allow modification of the pigment / polymer separately prior to combining the pigment with the polymer. In another embodiment, the at least one ionic polymer coating the pigment surface can be obtained by combining the pigment / synergist system with monomers which are then polymerized. One embodiment provides a method for producing composite particles comprising: combining a pigment with at least one ionic synergist adsorbed on the surface of the pigment; Coating the surface of the pigment comprising the at least one synergist with at least one ionic polymer, wherein the at least one synergist and the at least one polymer have opposite charges, and wherein in the composite, the total charge of the at least one polymer is greater than the total charge of the at least one synergist. The pigment having at least one ionic synergist adsorbed on its surface can be prepared by any method known in the art, for example by combining the at least one synergist and the pigment with a mixture, combination, agitation, homogenization, dispersion, etc. The pigment can then be combined with the polymer by similar methods or other methods known in the art. The combination can be carried out in a batch or continuous process. In one embodiment, the pigment and the ionic synergist (s) can be combined via a high shear mixture to break the pigment agglomerates. In addition, various treatments can be introduced during the preparation of the pigment composites to remove undesired materials. For example, diafiltration or dialysis may be used to remove unwanted impurities (eg free synergists) after mixing (eg, high shear mixing) of the pigment and synergists. In one embodiment, the pigment and charged synergist are first combined by high shear mixing to break the pigment agglomerates, followed by the addition of oppositely charged polymers with additional high shear mixing. In addition, various treatments can be introduced during the preparation of the pigment composites to remove undesired materials. For example, diafiltration or dialysis can be used to remove free synergists after mixing (eg high shear mixing) pigment and synergists, or pigment / synergist and polymers. The coating of the pigment surface comprising at least one synergist with at least one ionic polymer can be carried out by any method known in the art. In one embodiment, the coating is carried out by mixing under high shear.

Pigments In one embodiment, the pigment is an organic pigment, for example an organic colored pigment. The colored pigment may be blue, brown, cyan, green, purple, magenta, red or yellow, as well as mixtures thereof. Suitable classes of colored pigments include, for example, anthraquinones, phthalocyanine blues, phthalocyanine greens, diazo, monoazo, pyranthrones, perylenes, heterocyclic yellows, quinacridones, quinolonoquinolones, and thioamines. ) indigoid. These pigments are commercially available in powder or pressed cake form from many sources, including BASF Corporation, Engelhard Corporation, Sun Chemical Corporation, Clariant, and Dainippon Ink and Chemicals (DIC). In one embodiment, the pigment has no primary amines. Examples of phthalocyanine blues include copper phthalocyanine blue and its derivatives (Pigment Blue 15), such as PB15, PB15: 1, PB15: 2, PB15: 3, PB15: 4, PB15: 5, PB15: 6, PB16, PB17, PB17: 1, PB68, PB70, PB75, PB79 and PG7, PG13, PG36, PG37, PG48, PG58, which are commercially available from suppliers such as BASF Corporation, Sun Chemical Corporation, Clariant International Ltd. , DIC Corporation, and others. Examples of quinacridones include Pigment Orange 48, Pigment Orange 49, Pigment Red 122, Pigment Red 192, Pigment Red 202, Pigment Red 206, Pigment Red 207, Pigment Red 209, Pigment Violet 19 and Pigment Violet 42. Examples of anthraquinones include Pigment Red 43, Pigment Red 194 (peridone red), Pigment Red 216 (brominated pyranthrone red) and Pigment Red 226 (pyranthrone red). Examples of perylenes include Pigment Red 123 (vermilion), Pigment Red 149 (scarlet), Pigment Red 179 (burgundy), Pigment Red 190 (red), Pigment Violet, Pigment Red 189 (red shaded with yellow) ) and Pigment Red 224. Examples of thioindigoids include Pigment Red 86, Pigment Red 87, Pigment Red 88, Pigment Red 181, Pigment Red 198, Pigment Violet 36, and Pigment Violet 38. Examples heterocyclic yellows include Pigment Yellow 117 and Pigment Yellow 138. Examples of group I AS naphthol pigments include Pigment Red 8, Pigment Red 12, Pigment Red 13, Pigment Red 14, Pigment Red 15, Pigment Red 17, Pigment Red 22, and Pigment Red 23. Other suitable examples of pigments include yellow pigments such as Pigment Yellow 1, 74, 128, 139, 155, 180, 185, 213, 218, 220 and 221, red pigments such as Pigment Red 177, 185, 254 and 269, blue pigments such as Pigment Blue 16 and 60, orange pigments such as Pigment Orange 168, and green pigments such as Pigment Green 7 and 36. Examples of other suitable color pigments are described in Color Index, 5th edition (The Society of Dyers and Cikiyrusts, 1982). In one embodiment, the pigments are selected from azo pigments and the synergist is an azo compound which is a product of the azo coupling reaction of an aromatic or heterocyclic amine, containing one or more ionizable groups, with the same agent. azo coupling that used in the preparation of the azo pigment. The aromatic or heterocyclic amine may optionally have other non-ionizable substituents to achieve a sufficient degree of structural similarity with the parent pigment. For phthalocyanines or polycyclic pigments, such as diketopyrrolopyrrole (DPP) or perylenes, the synergists can be prepared for example by simple electrophilic substitution of the pigment, for example by sulfonation, to obtain an anionic synergist, or chlorosulfonation followed amidation with a polyfunctional amine to obtain a cationic synergist. In one embodiment, the synergist and / or the pigment have at least one attached organic group. The organic group may be an aliphatic group, a cyclic organic group, or an organic compound having an aliphatic portion and a cyclic portion. In one embodiment, the organic group is attached via a diazonium salt derived from a primary amine capable of forming, even transiently, a diazonium salt. The organic group may be substituted (for example by at least one ionic group, ionizable group, or mixtures thereof) or unsubstituted, branched or unbranched. Aliphatic groups include, for example, groups derived from alkanes, alkenes, alcohols, ethers, aldehydes, ketones, carboxylic acids, and carbohydrates. Cyclic organic groups include, but are not limited to, alicyclic hydrocarbon groups (e.g. cycloalkyl, cycloalkenyl), heterocyclic hydrocarbon groups (e.g., pyrrolidinyl, pyrrolinyl, piperidinyl, morpholinyl and the like), aryl groups (e.g. , naphthyl, anthracenyl), and heteroaryl (imidazolyl, pyrazolyl, pyridinyl, thienyl, triazolyl, furyl, indolyl, and triazolyl, such as 1,2,4-triazolyl and 1,2,3-triazolyl).

In one embodiment, the at least one attached organic group comprises at least one ionic group, an ionizable group, or mixtures of an ionic group and an ionizable group, as described herein.

In one embodiment, the at least one organic group is capable of binding calcium (e.g. having defined calcium indices), including the organic groups described in PCT Publication No. WO 2007/053564. For example, the organic group comprises at least one bisphosphonic acid paired group, its partial esters, or its salts, for example a group of formula -CQ (PO 3 F12) 2, its partial esters, or its salts, where Q is bound to paired position and may be H, R, OR, SR or NR2 where R ", which may be the same or different, are as defined above, or H, a saturated or unsaturated, branched C1-C8 alkyl group or unbranched, a saturated or unsaturated, branched or unbranched C1-C8 acyl group, an aralkyl group, an alkaryl group, or an aryl group. Nos. 042,643 and 6,641,656 disclose modified pigments having various attached groups, including phosphonic acid groups In one embodiment, the synergist or pigment is modified by at least one organic group via a diazonium treatment as detailed by for example, in the following patents: U.S. Patent Nos. 5,554,739; 630,868; 5,672,198; 5,707,432; 5,851,280; 5,885,335; 5,895,522; 5,900,029; 5,922,118; 6,042,643; 6,534,569; 6,398,858 and 6,494,943 (high shear conditions); 6,372,820; 6,368,239; 6,350,519; 6,337,358; 6,103,380; 7,173,078; 7,056,962; 6,942,724; 6,929,889; 6,911,073; 6,478,863; 6,472,471; and WO 2011/143533. In one embodiment, attachment is provided via a diazonium reaction in which the at least one organic group has a diazonium salt substituent. In another embodiment, the direct attachment may be formed using the stable diazonium and free radical processes described, for example, in US Pat. Nos. 6,068,688; 6,337,358; 6,368,239; 6,551,393; 6,852,158 which utilize the reaction of at least one radical with at least one particle, and in which a radical is generated by the interaction of at least one transition metal compound with at least one organic halide compound in the presence of one or more particles capable of radical uptake, and the like. The amount of attached organic groups may vary depending on the desired use of the modified pigment and the type of the attached group. For example, the total amount of organic group may be from 0.01 to 10.0 pmol of groups / m2 of pigment surface, as measured by nitrogen adsorption (BET method), including from 0.5 to 5 0 pmol / m2, 1 to 3 pmol / m2, or 2 to 2.5 umol / m2. Polymers The polymer may be a natural polymer or a synthetic polymer having a charge or capable of being charged, that is to say having at least one ionic or ionizable group, and mixtures thereof. The polymer may be chosen from polyelectrolytes and / or dispersants. Examples of natural polymers include proteins such as glue, gelatin, casein and albumin; natural rubbers such as gum arabic and gum tragacanth; glucosides such as saponin; alginic acid, and alginic acid derivatives such as propylene glycol alginate, triethanolamine alginate, and ammonium alginate; and carbohydrates, including cellulose derivatives such as methylcellulose, carboxymethylcellulose, hydroxyethylcellulose and ethylhydroxycellulose. Examples of synthetic polymers include polyvinyl alcohols; polyvinylpyrrolidones; acrylate-based polymers, for example acrylic or methacrylic resins and their copolymers (often written in "(meth) acrylic"), poly (meth) acrylic acid, acrylic acid / (meth) copolymers acrylonitrile, (meth) acrylate / (meth) acrylonitrile copolymers, vinyl acetate / (meth) acrylate copolymers, and (meth) acrylic acid / (meth) acrylate ester copolymers, styrene-acrylic or methacrylic resins such as styrene / (meth) acrylic acid copolymers, styrene / (meth) acrylic acid / (meth) acrylate ester copolymers, styrene / α-methylstyrene / acid (meth) copolymers acrylic, styrene / α-methylstyrene / (meth) acrylic acid / (meth) acrylate copolymers, and styrene / maleic acid copolymers; styrene / maleic anhydride copolymers, vinylnaphthalene / acrylic or methacrylic acid copolymers; copolymers of vinylnaphthalene / maleic acid; and vinyl acetate copolymers such as vinyl acetate / ethylene copolymers, vinyl acetate / vinylethylene fatty acid copolymers, vinyl acetate / maleate copolymers, acetate copolymers. vinyl / crotonic acid and copolymers of vinyl acetate / acrylic acid; as well as their salts. Other polymers include polyesters with charged groups such as sulfonates, and polyurethanes with charged groups, such as carboxylates, polyphenols and polyphenolates. The ionic polymers may also contain linear or branched polyamines such as polyethyleneimine (PEI), ethyleneimine oligomers (such as pentaethyleneamine, PEA), polyethyleneimine derivatives, and aminoacrylate polymers. (such as homo- or co-polymers of dimethylaminoethyl acrylate or methacrylate), PAMAM or other quaternary amine polymers, and polyallylamines. In one embodiment, the polymer is linear or branched. In one embodiment, the branched polymer is in the form of a star, a comb or a brush. In one embodiment, the polymer may be a random copolymer or a block copolymer. In one embodiment, the polymer is anionic and is selected from acrylate-based polymers, polyurethanes, and polyesters.

Dispersions and inkjet ink compositions An embodiment provides a dispersion comprising the pigment composites described herein and a liquid vehicle. The dispersion can be prepared using any method known in the art. For example, the dry modified pigment can be combined with the stirred liquid vehicle to produce a stable dispersion. Any equipment known in the art, such as a ball mill, or high shear mixing equipment, can be used, and various conventional milling media can also be used. The dispersion can be prepared by adding pigments and polymers having opposite charges by any method known in the art. In one embodiment, the pigment is subjected to high shear mixing to break the pigment agglomerates, and then, or at the same time, oppositely charged polymers are added by mixing again under high shear. Subsequent treatments include sonification, diafiltration and / or centrifugation. In addition, various treatments can be introduced during the preparation of pigment composites to remove undesired materials, such as diafiltration or dialysis. Other methods for forming the dispersion will be known to those skilled in the art. The liquid vehicle may be an aqueous or non-aqueous vehicle. In one embodiment, the vehicle contains water, for example the vehicle contains an aqueous solution. In one embodiment, the aqueous solution contains more than 50% by weight of water and may be, for example, water or mixtures of water with water-miscible solvents such as alcohols. In one embodiment, the amount of pigment without the polymer coating present in the dispersion may vary, but is typically an amount in the range of 0.1% to 40%, for example 1% to 40%, from 1% to 30%, from 1% to 25%, from 1% to 20%, from 1% to 15%, from 2% to 40%, from 2% to 30%, from 2% to 25%, 2% to 20%, 2% to 15%, 3% to 40%, 3% to 30%, 3% to 25%, 3% to 20%, or 3% to 15%, ratio to the total weight of the dispersion. In one embodiment, in a dispersion, the synergist / pigment weight ratio is in the range of 0.01 to 0.5. In another embodiment, in a dispersion, the polymer / pigment weight ratio is in the range of 0.01 to 3. In one embodiment, the dispersion has a total solids content within the range of ranging from 10% to 40% by weight relative to the total weight of the pigment, for example from 10% to 35%, from 10% to 30%, from 10% to 25%, from 10% to 20%, from 15% 40%, 15% to 35%, 15% to 30%, 15% to 25%, or 15% to 20% by weight based on the total weight of the pigment. In one embodiment, the dispersions disclosed herein are stable, as indicated by the properties that do not change by more than 20% as a result of aging by heating for 6 weeks at 60 ° C. These properties include particle size (e.g., average volume, mV as measured by Nanotrac) or viscosity. In another embodiment, properties such as particle size and viscosity do not change by more than 10% following heat aging for 6 weeks at 60 ° C. Another embodiment provides inkjet ink compositions comprising the dispersions disclosed herein. The amount of modified pigment used in the inkjet ink composition may vary, but is typically an amount effective to impart the desired image quality (e.g., optical density) without adversely affecting the performance of the inkjet ink composition. ink jet ink. In one embodiment, the pigments disclosed herein are present in the ink jet ink composition in an amount ranging from 0.1% to 20%, for example from 1% to 20%, of 1% to 10%, or 3% to 8%, based on the total weight of the inkjet ink composition.

The ink jet ink composition can be formed with a minimum of additional components (additives and / or co-solvents) and processing steps. However, suitable additives can also be added to these ink jet ink compositions to provide a number of desired properties while maintaining the stability of the compositions. For example, surfactants can be added to further enhance the colloidal stability of the composition. Other additives are well known in the art and include humectants, biocides and fungicides, binders such as polymeric binders; pH regulating agents, drying accelerators, penetrating agents, and the like. The amount of a particular additive will vary depending on various factors, but is generally present in an amount of from 0% to 40% based on the weight of the inkjet ink composition. Dispersants (surfactants and / or dispersants) may be added to further enhance the colloidal stability of the composition or to change the interaction of the ink with either the printing substrate, such as printing paper, or with the print head. Various anionic, cationic and nonionic dispersing agents may be used in conjunction with the ink composition of the present invention, and these may be used pure or in aqueous solution. The dispersing agent may be present in the ink jet ink composition in an amount of from 0.1% to 5%.

Representative examples of anionic surfactants or dispersants include, but are not limited to, higher fatty acid salts, higher alkyl dicarboxylates, sulfuric acid and higher alcohol ester salts, alkylsulfonates. alkylbenzenesulfonates, alkylnaphthalenesulfonates, naphthalenesulfonates (Na, K, Li, Ca, etc.), formalin polycondensation products, higher fatty acid and amino acid condensates, ester salts, and the like. of dialkylsulfosuccinic acid, alkylsulfosuccinates, naphthenates, alkylether carboxylates, acyl peptides, α-olefinsulfonates, N-acrylmethyltaurine, alkyl ether sulfonates, ethoxylated secondary alcohol sulfates, polyoxyethylenated alkylphenyl ether sulfates, monoglycylsulfates, alkyletherphosphates and alkylphosphates, alkylphosphonates and bisphosphonates, including hydroxyl derivatives or amines. For example, as anionic dispersing aids, polymers and copolymers of styrene sulfonate salts, substituted and unsubstituted naphthalenesulfonate salts (e.g., alkyl or alkoxy substituted naphthalene derivatives), aldehyde derivatives can be used. (such as unsubstituted alkylaldehyde derivatives, including formaldehyde, acetaldehyde, propylaldehyde, and the like), maleic acid salts, and mixtures thereof. The salts include, for example, Na +, Li +, K +, Cs +, Rb +, and substituted or unsubstituted ammonium cations. Representative examples of cationic surfactants include aliphatic amines, quaternary ammonium salts, sulfonium salts, phosphonium salts and the like. Representative examples of nonionic surfactants or dispersants useful in inkjet inks include fluorinated derivatives, silicone derivatives, acrylic acid copolymers, polyoxyethylenated alkyl ethers, polyoxyethylenated alkylphenyl ethers, alcohol ethers, and the like. polyoxyethylenated secondary ethers, polyoxyethylenated styrene ethers, ethoxylated acetylenic diols, polyoxyethylenated lanolin derivatives, oxyethylenated derivatives of formalin and alkylphenol condensates, block polymers of polyethylene oxide and poly (propylene oxide) ), the acid esters. polyoxyethylenated fatty acids, polyoxyethylenated polyoxypropylenated alkyl ether compounds, fatty acid and ethylene glycol esters of the condensation type with a poly (ethylene oxide), fatty acid monoglycerides, fatty acid esters and polyglycerol, fatty acid esters of propylene glycol, fatty acid esters of cane sugar, fatty acid alkanolamides, polyoxyethylenated fatty acid amides and polyoxyethylenated alkylamine oxides. For example, ethoxylated monoalkyl or dialkyl phenols may be used. These nonionic dispersants or surfactants may be used alone or in combination with the aforementioned cationic and anionic dispersants.

The dispersing agents may also be natural polymeric dispersants or synthetic polymers. Specific examples of natural polymeric dispersants include proteins such as glue, gelatin, casein and albumin; natural rubbers such as gum arabic and gum tragacanth; glucosides such as saponin; alginic acid and alginic acid derivatives such as propylene glycol alginate, triethanolamine alginate and ammonium alginate; and cellulose derivatives such as methylcellulose, carboxymethylcellulose, hydroxyethylcellulose and ethylhydroxycellulose. Specific examples of polymeric dispersants, including synthetic polymeric dispersants, include polyvinyl alcohols, polyvinylpyrrolidones, acrylic or methacrylic resins (often written in "(meth) acrylic") such as poly (acid) acrylics), acrylic acid / (meth) acrylonitrile copolymers, (meth) acrylate / (meth) acrylonitrile copolymers, vinyl acetate / (meth) acrylate copolymers, and acid copolymers (meth) acrylic / ester (meth) acrylate; styrene-acrylic or methacrylic resins such as styrene / (meth) acrylic acid copolymers, styrene / (meth) acrylic acid / (meth) acrylate ester copolymers, styrene / α-methylstyrene / acid (meth) copolymers acrylic, styrene / α-methylstyrene / (meth) acrylic acid / (meth) acrylate copolymers; styrene / maleic acid copolymers; styrene / maleic anhydride copolymers, vinylnaphthalene / acrylic or methacrylic acid copolymers; vinylnaphthalene / maleic acid copolymers; and vinyl acetate copolymers such as vinyl acetate / ethylene copolymers, vinyl acetate / vinylethylene fatty acid copolymers, vinyl acetate / maleate copolymers, copolymers of vinyl acetate / ethylene, vinyl acetate / crotonic acid and copolymers of vinyl acetate / acrylic acid; as well as their salts. In addition, the ink and ink compositions may further incorporate colorants for modifying the color balance and adjusting the optical density. These dyes include food dyes, FD & C dyes, acid dyes, direct dyes, reactive dyes, phthalocyanine and sulfonic acid derivatives, including copper phthalocyanine derivatives, sodium salts, sodium salts and the like. ammonium salts, potassium salts, and lithium salts.

Examples The following examples describe the preparation of aqueous pigment dispersions which are first dispersed by cationic synergists, then becoming anionic pigment dispersions by the addition of anionic polymer dispersants. These pigment dispersions exhibit improved properties over comparative examples, which include an anionic polymer dispersed pigment dispersion, an anionic synergist dispersed pigment dispersion, and a pigment dispersion first dispersed by surfactants. conventionally, followed by the addition of anionic polymer dispersants. Example 1 This example describes the synthesis of a "cationic synergist I" synergist. The summary scheme is shown below. To a 250 ml Erlenmeyer flask are charged 14.6 g of 1- (4-aminophenyl) pyridin-1-ium chloride ("PyCl"), 20 g of deionized ice water and 80 g of water. deionized, with stirring. After all the solid PyCl has been dissolved, 40 ml of 2M sodium nitrite is added to this solution which is then placed in an ice-water bath and cooled to less than 5 ° C. In a separate 500 ml Erlenmeyer flask immersed in an ice-water bath, 50 ml of deionized ice water and 200 ml of 1 M HCl solution are added. The amine is subjected to the prepared PyCl solution. above to a diazotization by dropwise addition of cold HC1 solution. Excess nitrous acid is destroyed by adding about 2 g of sulfamic acid. This diazo-PyCl solution is maintained in an ice-water bath until used in the coupling reaction.

In a separate 2 liter flask, 22.89 g of N- (5-chloro-2-methoxyphenyl) -3-hydroxy-2-naphthamide (available from TCI under the name Naphthol AS-CA) is dissolved in 37, 5 ml of a solution of 2M NaOH and 250 ml of ethanol. The resulting solution is cooled to 5 ° C. To this solution is added dropwise the diazo-PyCl solution with vigorous stirring over a period of 40 minutes to 1 hour. As the solution becomes very viscous during the addition period, another 200 ml of ethanol and 300 ml of methanol are added to ensure good mixing. During the entire period of addition, about 50 ml of 2M NaOH was added to the reaction mixture to maintain a pH greater than 12. The reaction mixture was allowed to rise gradually to room temperature and then stirred at room temperature until the reaction was complete. on the next day. The resulting red precipitate is filtered off, washed with deionized water and dried in a vacuum oven at 60 ° C to give 32.4 g of the cationic synergist I.

Example 2 This example describes the preparation of a composite comprising a pigment, a synergist, and a polymer having an opposite charge and greater than that of the synergist. The polymer used in this example is Joncryl® 683, a styrene-acrylic acid copolymer available from BASF having an acid number of 165 and a MW of 7000-9000. 3.3 g of the cationic synergist I prepared in Example 1 are combined with 73.3 g of Pigment Red 269 (pressed cake at 46.4% solids, available from Sun Chemical Corporation, Cincinnati, OH) and 128 g. g deionized water. This mixture is sonicated at about 10 ° C with a Misonix® probe sonifier for 1 hour to obtain a low viscosity red dispersion having an average particle size of about 255 nm (determined using a particle size analyzer). Microtrac0). To this PR269 dispersion was added 30.1 grams of Joncry® 6883 polymer solution (7.65 grams of Joncryl® 683 and 1.25 grams of KOH in 21.2 grams of deionized water) with rapid stirring. During the addition of the Joncryl® 683 polymer solution, the viscosity of the dispersion increases to a gel and then becomes a low viscosity final mixture. The viscosity likely results from changes in the surface charges of the PR269 dispersion from an initial cationic charge to an anionic final charge. The mixture is then allowed to stir for a period of time. 5 minutes, giving particles having an average particle size of about 244 nm. The dispersion was sonicated at about 10 ° C for an additional hour to give a red dispersion having an average particle size of about 163 nm. The resulting dispersion is centrifuged at 2500 g for about 30 minutes and then decanted to isolate the product. 320 g of a final aqueous dispersion of Joncryl® 683 / PR269 dispersed with the cationic synergist I, containing 12.6% solids, are obtained. Table 1 below lists the final particle size distribution. Example 3 3.3 g of the cationic synergist I prepared in Example 1 were combined with 73.3 g of Pigment Red 269 (46.4% pressed cake (11% dry), available from Sun Chemical Corporation, Inc. This mixture is sonicated at about 10 ° C with a Misonix® probe sonifier for 1 hour to obtain a weakly viscous red dispersion having an average particle size of about 10 hours. about 180 nm, 40 g of Joncryl® 683 polymer solution (5.1 g of Joncryl® 683 and 0.84 g of KOH in 34.06 g of deionized water) were added to this PR269 dispersion with rapid stirring. During the addition of the Joncryl® 683 pollen solution, the viscosity of the dispersion increases to a gel and then returns to a low-viscosity final mixture. surface charges of the PR269 dispersion passing from an initial cationic charge at an anionic final charge. The mixture is then allowed to stir for 5 minutes to give particles having an average particle size of about 200 nm. The dispersion is sonicated at about 10 ° C for another hour. The resulting dispersion was centrifuged at 2500 G for about 30 minutes and then decanted to isolate the product. 270 g of a final aqueous dispersion of Joncryl® 683 / PR269 dispersed with the cationic synergist I, containing 15% solids (see Table 1 for particle size distribution) are obtained. Comparative Example A This example describes the preparation of a pigment / polymer dispersion without synergist. 29.5 g of Joncryl® 683 polymer solution (7.5 g of Joncryl® 683 and 1.24 g of KOH in 20.76 g of deionized water) are combined with 86.2 g of Pigment Red 269 (cake). pressed at 46.4% solids, available from Sun Chemical Corporation, Cincinnati, OH) and 128 g of deionized water, and sonicated at about 10 ° C with a Misonix® probe sonifier. for 1 hour to obtain a red dispersion having an average particle size of about 165 nm. After sonication, the dispersion is sonicated for another hour, the resulting dispersion is centrifuged at 2500 G for about 30 minutes and then decanted to isolate the product. 240 g of a final aqueous dispersion of PR269 dispersed with Joncryl® 683, containing 18.9% solids (see Table 1 for particle size distribution) are obtained. For this dispersion, the viscosity remains low and the surface roughness remains anionic throughout the period. Comparative Example B This example describes the preparation of a pigment / synergist dispersion without polymer. The anionic PR269 synergist, described below, can be prepared, for example, using the procedure described in US Pat. No. 7,223,302 B2. CI Synergist I PR269 3.2 g of synergist I PR269 are combined with 0.91 g of a 45% solution of KOH, 69 g of Pigment Red 269 (cake pressed at 46.4% solids, available from Sun Chemical Corporation, Cincinnati, OH) and 162 g of deionized water. The mixture is sonicated at about 10 ° C with a Misonix® probe sonifier for 1 hour to obtain a red dispersion having an average particle size of about 158 nm. This dispersion is then sonicated for another hour. The resulting dispersion was centrifuged at 2500 g for about 30 minutes and then decanted to isolate the product. 220 g of a final aqueous dispersion of PR269 dispersed with the synergist containing 15.2% solids (see Table 1 for the particle size distribution) are obtained. For this dispersion, the viscosity is low and the surface charges remain anionic throughout the period.

Comparative Example C This example describes the preparation of a cationic pigment / surfactant dispersion further combined with an anionic polymer, wherein the cationic surfactant is not a synergist. 1.33 g of cetyltrimethylammonium bromide cationic surfactant (CTAB) were combined with 69 g of Pigment Red 269 (pressed cake at 46.4% solids, available from Sun Chemical Corporation, Cincinnati, OH) and 138 g of deionized water, and sonicated at about 10 ° C with a Misonix® probe sonifier for 1 hour to obtain a low viscosity red dispersion having an average particle size of about 154 nm. 45.8 g of Joncryl® 683 polymer solution (6.0 g of Joncryl® 683 and 0.99 g of KOH in 38.8 g of deionized water) were added to this PR269 dispersion with rapid stirring. During the addition of the Joncryl® 683 polymer solution, the viscosity of the dispersion increases to a gel and then becomes a low viscosity final mixture. The viscosity likely results from changes in the surface charges of the PR269 dispersion from an initial cationic charge to an anionic final charge. After the addition is complete, the mixture is allowed to stir for 5 minutes to give particles having an average particle size of about 203 nm. The dispersion is sonicated at about 10 ° C for an additional hour to give a red dispersion having an average particle size of about 145 nm. The resulting dispersion was centrifuged at 2500 G for about 30 minutes and then decanted to isolate the product. 260 g of a final aqueous dispersion of Joncryl® 683 / PR269 dispersed with CTAB, containing 14.1% solids (see Table 1 for the granulometry distribution) are obtained: TABLE 1 Samples Dispersant composition % dry extract pH Average Particle Size (nm) Dioo Particle Size (nm) for Pigment Red 269 Example 2 Cationic Synergist I and 12.6 8.76 155 486 Joncryl® 683 Example 3 Cationic Synergist I and 15.0 8.70 150 409 Joncryl® 683 Example Joncryl® 683 18.9 9.40 144 409 Comparative A Example Synergist PR269 I 15.2 9.63 138 344 Comparative B Example CTAB cationic and Joncryl® 14.1 8.45 145 409 Comparative C 683 Example 4 This example describes the preparation of inkjet ink compositions and a stability test. The aqueous dispersions of Examples 2 and 3 and Comparative Examples A-C were combined with the components of Table 2 to prepare ink compositions. The pH, the particle size distribution (ie the average particle size and the D100 particle size) are immediately recorded and the viscosity of these five inks after the preparation of the inks (time = initial) and after 1 week of heating in an oven at 60 ° C (time = week 1). The recorded physical characteristics of the inks are shown in Table 3. Duo is the largest grain size of the measurements, for which 100% of the particle population is less than Dmo.

Table 2 Ingredient Quantity () A by weight) Pigment br, t% Glycerol 40% Surfynol 465 * 1.0% Water 54.5% * SURFYNO1® 465 is a nonionic surfactant from Air Products.

Table 3 Samples Time pH Granulometry Granulometry Mean viscosity (nm) at 100% (nm) (cP) Example 2 Initial 8.41 147 409 4.22 Week 1 8.26 179 687 6.22 Example 3 Initial 8.41 154 409 5.08 Week 1 8.05 196 578 7.22 Initial Example 8.52 135 344 4.72 Comparative A Week 1 8.42 451 1635 17.3 Initial Example 8.69 133 344 4.94 Comparative B Week 1 8 , 76 388 972 15.3 Example Initial 8.08 140 409 4.26 Comparative C Week 1 7.99 691 2750 14.3 As is evident from the results of Table 3, the recording inks by ink jet of the composite PR269 particles of Examples 2 and 3, wherein the pigments are first dispersed by cationic synergists and then combined with anionic polymer dispersants, exhibit excellent stability, i.e. small changes in particle size distribution (mean particle size) and viscosity after 1 week of heating. In contrast, (1) the ink jet recording ink of Comparative Example A, which comprises dispersions of PR269 dispersed solely by an anionic polymer dispersant, becomes very unstable after 1 week of heating, as evidenced by an increase of more than 230% in the average particle size and a jump of more than 260% in viscosity; (2) the ink jet recording ink of Comparative Example B, which comprises PR269 particles dispersed solely by anionic synergists, becomes very unstable after 1 week of heating, as evidenced by an increase in more than 190% of the average particle size and a leap of more than 210% in the viscosity; (3) the ink jet recording ink of Comparative Example C, which comprises dispersions of PR269 first dispersed by a non-synergistic cationic surfactant (CTAB) and further combined with anionic polymer dispersants, becomes very unstable after 1 week of heating, as evidenced by an increase of more than 390% in the average particle size and a jump of more than 230% in viscosity. Example 5 This example describes the preparation of a PB15: 4 dispersion containing Basic Blue 140, having the structure below: 155.3 g of Pigment Blue 15: 4 (32.4% pressed cake) , obtained from Sun Chemical), equivalent to 50 g of dry pigment, with 12.5 g of KRL Liquid Cartasol Turquoise (Basic Blue 140, CAS # 61724-62-7, Clariant Corporation, dye content about 20%) and . 183 ml of DI water. The mixture was homogenized using a Silverson LR4RT-A rotor-stator mixer for 60 minutes and then sonicated for 60 minutes using the 183 MW Misonix discontinuous sonifier. diafiltration on a 50 nm GE membrane until the conductivity reaches 250 microsiemens and centrifuged at 2500 g for 30 minutes. The resulting cationic dispersion has a Mv of 100.9 nm (Nanotrac) and a solids content of 13.2. ## STR1 ## x = 3-4 Example 6 This example describes the preparation of a PB15: 4 dispersion containing Direct Blue 86 having the following structure: Direct Blue 86 NaO3S 155.3 g of Pigment Blue 15: 4 ( 32.4% pressed cake, obtained from Sun Chemical), equivalent to 50 g of dry pigment, with 4.5 g of Direct Blue 86 (TCI Chemicals, 89% dye content, the rest is sodium chloride and sodium sulfate, the dye content is 4 g or 8% based on the weight of the pigment) and 200 ml of DI water. The mixture was homogenized using a Silverson LR4RT-A rotor-stator mixer for 60 minutes and then sonicated for 60 minutes using the 183 MW Misonix discontinuous sonifier. The dispersion was diafiltered over a GE membrane of 50 nm until the conductivity reaches 250 microsiemens and centrifuged at 2500 g for 30 minutes. The resulting cationic dispersion has a Mv of 134.3 nm (Nanotrac), a sodium counterion content of 3454. ppm (based on the solids content) and a solids content of 12.0%. Example 7 This example describes the preparation of a PB15: 4 dispersion containing Direct Blue 199, which is a tetrasulphonated copper phthalocyanine tetrasodium salt. The procedure of Example 6 was used with 16 g of Direct Blue 199 (Permalite FBL 400% by dyestuff standard, the dye content was 60%, the remainder was sodium chloride and sulphate sodium, the pure dye content is 4 g or 8% based on the weight of the pigment). The resulting cationic dispersion has a Mv of 126.8 nm (Nanotrac), a sodium counterion content of 2887 ppm (based on the solids content) and a solids content of 10.9%. Example 8 This example describes the preparation of a PB15: 4 dispersion containing Acid Blue 185, which is a trisodium salt of trisulphonated copper phthalocyanine. The procedure of Example 6 was used with 16 g of Acid Blue 185 (Permalon M5G by dyestuff standards, the dye content was 60%, the remainder was sodium chloride and sodium, the pure dye content is 4 g or 8% based on the weight of the pigment). The cationic dispersion obtained has a Mv of 123.4 nm (Nanotrac), a sodium counterion content of 2247 ppm (based on the solids content) and a solids content of 13.2%. EXAMPLE 9 Heat Aging Heat aging of the dispersions as is and in aqueous mixture at 4% solids content containing 10% of triethylene glycol monobutyl ether (TEGMBE) is carried out. The materials are heat-aged for 6 weeks at 60 ° C, and the particle size, viscosity and filterability (-1 μm polypropylene syringe filter) are measured after 1, 2 and 6 weeks. The physical properties of these samples after heat aging at 60 ° C for 6 weeks are shown in Table 4. Table 4 also shows the percent change in each property.

Table 4 Example Synergist% Change% Change Mv Viscosity Basic Blue 140 5 5 Successful 6 Direct Blue 86 -9 3 Successful 7 Direct Blue 199 -1 3 Successful 8 Acid Blue 185 -1 -1 Successful 1 + TEGMBE Basic Blue 140 7 7 Successful 2 + TEGMBE Direct Blue 86 -1 5 Successful 3 + TEGMBE Direct Blue 199 7 7 Successful 4 + TEGMBE Acid Blue 185 1 5 Successful A change in physical properties of less than 5 20% indicates a stable dispersion. From Table 4, it can be seen that changes in physical properties are well within acceptable limits (changes less than 10%) for each dispersion of Examples 5 to 8.

The use of the terms "a", "an" and "the" must be understood as covering both the singular and the plural, unless otherwise indicated herein or unless clearly contradicted by the context. The terms "comprising", "having", "encompassing" and "containing" are to be understood as open terms (that is, "including, but not limited to") unless otherwise indicated. The recitation of ranges of values is here merely intended to serve as an abbreviated method for individually referring to each separate value in such a range, unless otherwise indicated, each separate value being incorporated in this description as if individually indicated therein. All the methods described here can be implemented in any order, unless otherwise specified or unless clearly contradicted by the context. The use of any or all of the examples, or an illustrative vocabulary (e.g. "such as"), proposed herein, is intended solely to further illuminate the invention and does not impose any limitation within the scope of the invention, unless otherwise stated.

Claims (32)

REVENDICATIONS1. Composite particles comprising: a pigmeht; at least one adsorbed pigment of pigment 1 and at least one pigment-coating polymer comprising the at least one synergist, in which the at least one synergist a polymer has opposite charges, and wherein in the composite of at least one polymer is greater than that of the at least one synergist. and the at least total charge total charge on the surface the surface of 15 2. -Parttlrteirempempites according to claim 1, wherein the coating comprises the at least one polymer partially coating the pigment. 3. Composite particles according to claim 1, wherein the coating comprises the at least one polymer encapsulating the pigment. Composite particles according to any of claims 1 to 3, wherein the at least one synergist is anionic and the at least one polymer is cationic; 5. Composite particles according to any one of claims 1 to 3, wherein the at least one synergist is cationic and the at least one anionic polymer. 6. Composite particles according to any one of claims 1 to 5 in which the at least one ionic synergist is selected from carboxylic acid, diadide sulfonic acid, phosphonic acid, hydroxyl, and 'amines.- 7. Composite particles according to any one of claims 1 to 6, which particles have a mean particle size in the range of 50 hm. at 600 nm. 8. Composite particles according to any one of claims 1 to 6, which particles have a mean particle size in the range of 50 nm to 400 nm. 9. Composite particles according to any one of claims 1 to 6, which particles have a mean particle size in the range of 50 nm to 200 nm. 10. Composite particles according to any one of claims 1 to 9, wherein the pigment is an organic pigment. 20 11. Composite particles according to any one of claims 1 to 10, in which the at least one ionic polymer is chosen from the salts of carboxylic acids, of sulphonic acids, of phosphonic acids, of hydroxyls, and amines. Composite particles according to any one of claims 1 to 11, wherein the at least one polymer is anionic and is selected from acrylate-based polymers, polyurethanes, and polyesters. Composite particles according to any one of claims 1 to 12, wherein the at least one polymer has an acid number of at least 20%. Composite particles according to Claim 13, in which the at least one polymer is chosen from polyurethanes: 15. Composite particles according to any one of claims 1 to 12, wherein the at least one polymer has an acid number of at least 50. Composite p-exticules according to claim 15, wherein the at least one polymer is selected from acrylate-based polymers. 10 Composite particles according to any one of claims 1 to 16, wherein the synergist / pigment weight ratio is in the range of 0.01 to 0.5. 15 18. Composite particles according to any one of claims 1 to 17, wherein the polymer / pigment weight ratio is in the range of 0.01 to 3. 19. Composite particles according to any one of claims 1 to 18, wherein the pigment and the at least one synergist have at least one attached ionic group. 25 20. Composite particles according to any one of claims 1 to 19, wherein the at least one synergist is a derivative of the pigment. 30 21. Composite particles according to any one of claims 1 to 20, wherein the pigment and the at least one synergist are derivatives of the same chromophore. 22. A dispersion comprising the composite particles of any one of claims 1 to 21. 23. Dispersion according to claim 22, in which, after aging at 60 ° C for 7 days, the average particle size of the composite particles increases by no more than 200% of the initial average particle size, 24. The dispersion of claim 22 wherein, after aging at 60 ° C for 7 days, the average particle size of the composite particles increases by no more than 100% of the initial average particle size. 10 25. Dispersion according to claim 22, wherein, after aging at 60 ° C for 7 days, the average particle size of the composite particles increases by at most 50% of the initial average particle size. 15 26. Dispersion according to claim 22, wherein, after aging at 60 ° C for 7 days, the viscosity of the dispersion increases by not more than 100% of the initial viscosity. 20 27. The dispersion according to claim 22, wherein, after aging at 60 ° C for 7 days, the viscosity of the dispersion increases by not more than 50% of the initial viscosity. 25 28. The dispersion of any one of claims 22 to 27, wherein the pigment is present in the dispersion in an amount in the range of 1% to 30%. 30 29. An ink jet ink composition comprising the composite particles of one. any of claims 1 to 21 in a liquid vehicle. Ink jet ink composition according to claim 29, wherein the liquid vehicle is an aqueous vehicle. 47 3014884 31. An ink jet ink composition comprising the dispersion of any one of claims 22 to 28. 32. A process for producing composite particles, comprising combining a pigment with at least one ionic synergist adsorbed on the surface of the pigment; the coating of the surface of the pigment comprising at least one synergist with at least one ienic polymer, wherein the at least one synergist and the at least one polymer have opposite charges, and wherein in the composite the The total charge of the at least one polymer is greater than the total charge of the at least one synergist.